11 research outputs found

    Pickering emulsion-enhanced interfacial biocatalysis: tailored alginate microparticles act as particulate emulsifier and enzyme carrier

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    A robust Pickering emulsion stabilized by lipase-immobilized alginate gel microparticles with a coating of silanized titania nanoparticles is developed for biphasic biocatalysis. The good recyclability and high stability of the proposed interfacial catalysis system have been verified, retaining about 90% of relative enzyme activity in 10 catalytic cycles with operation for 240 h. Meanwhile the Pickering emulsions remain stable during a storage time of one year. The green system can be widely applied to construct powerful platforms for enzyme or microorganism-driven interfacial catalysis

    Threshold Strategy for Nonsmooth Filippov Stage-Structured Pest Growth Models

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    In order to control pests and eventually maintain the number of pests below the economic threshold, in this paper, based on the nonsmooth dynamical system, a two-stage-structured pest control Filippov model is proposed. We take the total number of juvenile and adult pest population as the control index to determine whether or not to implement chemical control strategies. The sliding-mode domain and conditions for the existence of regular and virtual equilibria, pseudoequilibrium, boundary equilibria, and tangent points are given. Further, the sufficient condition of the locally asymptotic stability of pseudoequilibrium is obtained. By numerical simulations, the local bifurcations of the equilibria are discussed. Our results show that the total number of pest populations can be successfully controlled below the economic threshold by taking suitable threshold policy

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    3-Dimensional Porous Carbon with High Nitrogen Content Obtained from Longan Shell and Its Excellent Performance for Aqueous and All-Solid-State Supercapacitors

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    Three-dimensional porous carbon is considered as an ideal electrode material for supercapacitors (SCs) applications owing to its good conductivity, developed pore structure, and excellent connectivity. Herein, using longan shell as precursor, 3-dimensional porous carbon with abundant and interconnected pores and moderate heteroatoms were obtained via simple carbonization and potassium hydroxide (KOH) activation treatment. The electrochemical performances of obtained 3-dimensional porous carbon were investigated as electrode materials in symmetric SCs with aqueous and solid electrolytes. The optimized material that is named after longan shell 3-dimensional porous carbon 800 (LSPC800) possesses high porosity (1.644 cm3 g−1) and N content (1.14 at %). In the three-electrode measurement, the LSPC800 displays an excellent capacitance value of 359 F g−1. Besides, the LSPC800 also achieves splendid specific capacitance (254 F g−1) in the two electrode system, while the fabricated SC employing 1 M Li2SO4 as electrolyte acquires ultrahigh power density (15930.38 W kg−1). Most importantly, LSPC800 electrodes are further applied into the SC adopting the KOH/polyvinyl alcohol (PVA) gel electrolyte, which reaches up to an outstanding capacitance of 313 F g−1 at 0.5 A g−1. In addition, for the all-solid-state SC, its rate capability at 50 A g−1 is 72.73% and retention at the 10,000th run is 93.64%. Evidently, this work is of great significance to the simple fabrication of 3-dimensional porous carbon and further opens up a way of improving the value-added utilization of biomass materials, as well as proving that the biomass porous carbons have immense potential for high-performance SCs application

    The comparison of health status between male and female medical radiation workers in China

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    To assess the health statue of chronically exposed Chinese medical radiation workers. A cross-sectional study of 530 medical radiation workers in a city of China was conducted to document the health status and the monitored annually absorbed doses. Long-term and low-dose radiation exposure can affect a number of health indicators in the individuals, which covered the cardiovascular system, hematologic system, ophthalmology, liver and kidney's functions, chromosome aberration and micronucleus. The differences in the health status between male and female individuals were associated with job types and exposed years of service. The monitored doses of individuals were lower than the limit value of the national standard. The health status in chronically exposed individuals demonstrated some gender difference associated with length of exposure and work type. This study provides some evidence to understand the health status of medical radiation workers in China and have the potentially to inform screening and clinical diagnosis

    Nanomaterials for Delivering Antibiotics in the Therapy of Pneumonia

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    Bacterial pneumonia is one of the leading causes of death worldwide and exerts a significant burden on health-care resources. Antibiotics have long been used as first-line drugs for the treatment of bacterial pneumonia. However, antibiotic therapy and traditional antibiotic delivery are associated with important challenges, including drug resistance, low bioavailability, and adverse side effects; the existence of physiological barriers further hampers treatment. Fortunately, these limitations may be overcome by the application of nanotechnology, which can facilitate drug delivery while improving drug stability and bioavailability. This review summarizes the challenges facing the treatment of bacterial pneumonia and also highlights the types of nanoparticles that can be used for antibiotic delivery. This review places a special focus on the state-of-the-art in nanomaterial-based approaches to the delivery of antibiotics for the treatment of pneumonia

    Preparation of Nickel Nanoparticles by Direct Current Arc Discharge Method and Their Catalytic Application in Hybrid Na-Air Battery

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    Nickel nanoparticles were prepared by the arc discharge method. Argon and argon/hydrogen mixtures were used as plasma gas; the evaporation of anode material chiefly resulted in the formation of different arc-anode attachments at different hydrogen concentrations. The concentration of hydrogen was fixed at 0, 30, and 50 vol% in argon arc, corresponding to diffuse, multiple, and constricted arc-anode attachments, respectively, which were observed by using a high-speed camera. The images of the cathode and anode jets were observed with a suitable band-pass filter. The relationship between the area change of the cathode/anode jet and the synchronous voltage/current waveform was studied. By investigating diverse arc-anode attachments, the effect of hydrogen concentration on the features of nickel nanoparticles were investigated, finding that 50 vol% H2 concentration has high productivity, fine crystallinity, and appropriate size distribution. The synthesized nickel nanoparticles were then used as catalysts in a hybrid sodium–air battery. Compared with commercial a silver nanoparticle catalyst and carbon black, nickel nanoparticles have better electrocatalytic performance. The promising electrocatalytic activity of nickel nanoparticles can be ascribed to their good crystallinity, effective activation sites, and Ni/NiO composite structures. Nickel nanoparticles prepared by the direct current (DC) arc discharge method have the potential to be applied as catalysts on a large scale
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